Magnetization as a Stabilizing Influence on Ferrofluid Electrosprays*

Electrospray fills a gap for satellite propulsion, producing more thrust per weight or power than present alternatives. Useful thrust requires many electrospray emitters and multiplexing emitters to a useful scale often erodes performance. Current technologies like porous beds experience hurdles of repeatability. We exploit ferrofluids’ self-assembly into arrays of sharp tips as an alternative route to multiplexing electrosprays, demonstrating separations as low as 150um and tip curvatures as sharp as 5um. A novel, low volatility, low conductivity ferrofluid is produced, characterized and electrosprayed. Magnetization drastically expands spray stability, reducing the minimal stable flow rate by up to 99%, halving the onset voltage and showing distinctly non-Taylor morphology.